Heating insulation



July. 21, 1931. w.-|=Fr :n=|=ER HEATING INSTALLATION Filed April 16,1928

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W. PFEIFFER HEATING INSTALLATION Filed April- 16, 192s 2 sums-'sheet 2 lll,

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Patented July 21, 1931 UNITED. STATES PATENT OFFICE WILHELM PFEIFFER, OF -KAADEN-ONJJIHFI-IEIGEIR, CZECHOSLOVAKIA, ASSIGNOR OF ONE-THIRD TO KURTREISS, OF SAAZ-ON-THE-EGER, CZECHOSLOVAKIA.

HEATING INSULATION Application led April 16, 1928, Serial No. 270,421, and in Germani,r December 7, 1927.

My invention relates to heating installations for any'purpose, kitchen ranges, central heating systems, etc., of the type known as storage hearths., and it is an object of my .5 invention to provide a more efficient and economic installation of this'kind than has heretofore been constructed.

To this end instead of the usual cast iron blocks which were provided in kitchen ranges l@ or the like for storing heat, I provide a body of liquid which is evaporated in the storage block, condensed at the heating station or stations, and preferably returned to the storage block.

The old method'of storing heat in a cast iron block which'v generally is heated electrically,.involves the drawback of excessive heat loss. It is attempted to prevent such loss by placing on top of the block a heat 2@ insulated hood but this expedient is useless on accountpof the high temperature range,

300 to 500 degs. centigrade, at which the hood notwithstanding its insulation gradually be comes heated and radiates heat.

Another `drawback is the considerable weight of the storage block. The block con- .s stitutes the top plate of the kitchen range and must be supported byv heavy structures of strong and heat conducting material entailing corresponding convection loss. ,X

Still another drawback of the usual storage block is that accessories as roasting grids or grills which are indispensable for the operation of a kitchen, can not be supplied with heat on the storage principle, but require special connections and cause considerable peak loads in the electric system.

These drawbacks are overcome in my invention inpwhich the heat is not stored permanently in the storage block but transmitted to a liquid with which it may be conveyed to heating stations, cooking plates, grids, radiators, etc. The evaporated liquid circulates in a closed system and its steam or vapour is condensed at the heating station and returned to the evaporator.

`A suitable medium would be water but steam is at the critical range at a boiling temperature of 374 degs. centigrade, and at a pressure of more than 20() kilograms per squ. centimetre. However, it is desirable that the pressure of the medium should be as low as possible at operating temperatures of 350 to 450 degs. centigrade in order to transmit the heat rapidly, and von the other hand, the freezing pointofthe medium should be as low as practicable. The most suitable media are mercury, glycerine, linseed oil and diphenyl oxide.

In the pipe line between the heating station and the evaporating station an apparatus is conveniently inserted which controls the return of the condensed heating medium into the evaporator at will. This apparatus can consist of an elastic tubular bend adapted to be raised and lowered by hand which collects the condensate medium in the up position and allows it to flow back to the evaporator in the down position, or it may be a` man ually operated valve which in its closed position collects the heating medium and in the open-position allows it to return to the evaporator. This valve can be adapted to close gradually and automatically on an increase in pressure of the heating medium. It can -further in special cases be constructed as a check valve in order to maintain a low pressure in the condensate pipe during intervals of operation. The valve can be controlled by a diaphragm which is under the pressure of the medium.

My invention may be modilied in various ways according to the purpose for which it is to be used, and by way of example I shall describe an electric Vheating installation for hearth and a fuel fired central heating system.

Reference is to be had to the accompanying drawings, in whichI Fig. l is a diagrammaticelevation of an electric heating installation,

Fig. 2 is a section of a control valve for this installation on a larger scale,

` Fig. 8 is av perspective illustration of a grid or a grill adapted to be connected with the installation in Fig. 1,

Fig. 4 is a diagrammatic sectional elevation of a central heating system.

Referring now to Fig. l, an evaporator coil 2 is disposed in the storage block 1 from which a p-ipe b leads to the heating stationJS. The

latter is connected with a siphon f to which a bend formed of iiexible pipes e and t is connected and irom which a pipe c returns to the evaporator 'coil 2.l The bendy is engaged by a clamp d which is controlled by means of a link 4 through a handle a. If'the ha-ndle-a be in the down position indicated in dotted lines the clamp4 d with the bent pipes e t isin the up position vin Which position the bend prevents the flow of condensate to l the evaporator coil so that the condensate collects in the tube e in front of the bend and is not subjected to further evaporation. When the par/ts be in the position indicated in full linesrthe condensate can return again to the'evaporator coil 2 and the cycle begins anew. The position indicated in the drawings in full line is the heating position whilst in the position indicated in dotted lines the heating action is cut out. Graduated heating can be obtained byl adjusting the handle a into intermediate positions. Y

The evaporator coil 2 consists of a ho-rizontal tubular spiral cast in the storage-block which coil has a greater diameter than the pipe line, so that the quantity of liquid is distributed throughout the coil but does not completely fill it even at full return flow of condensate. This causes rapid evaporation Without trouble as surging and bumping. The steam is dried and superheated. A similar coil is providedat the heating station 3 which may beexposed or surrounded by a block of suitable material, aluminium, cast iron or the like. The storage block 1, the

. pipes, the heating station etc. are insulated as usually. A

Y The stora eblock 1 is suspended on steel Wires or ro s g so'that the convection`loss is very low. Further there arel disposed in front and .behind it hot Water receptacles 5 which absorb the major part of the radiated heat. A 4copper sheet 'i connecting both the -hot water 'receptacles' 5 absorbs the downwardly radiated heat and conducts it to the hot water receptacles 5. The storage block is heated by an electrical heating member h. A stand-by heating member h4 and a stand-by evaporating cil 36' may be provided. The receptacles 5, -5 may be combined into an annular reservoir surrounding the block 1.'

' In the case of a grill as shown in Fig. 3, the coil is preferably not embedded in a'block as this would involve loss of heat. The grid consists of a steam pipe 6 to which is led the evaporatedy heating medium through a si hon 7 Into thevtube 6 severaparallel an apo' proximately horizontally arranged cross 6 j fa. horizontal escape or outlettube V9 extending 'at approximately right angles thereto,-

tubes 8 open, which latter communicate with and from which the cooled heating medium is a' ainl delivered tdthe evaporator 2.

tubes'fS may conveniently have a slight drop towards the escape tube 9. The siphon 7 prevents the condensate flowing back to the evaporator 2.

By this constructional form at the heating station large radiation surfaces are obtained with less weight and on the other hand the .loss of heat is considerably reduced.

siliently mounted in a circular yoke 11. The

oke 11 is secured on a spindle 7c having on its upper end 'a disc 12'which is movable u and down in a bore 13 of the casing. spring o is arranged to bear against the disc 12 the other end of the spring bear-ing against a movable plate p disposed in the bore 13, the said movable plate p being adjustable by an eccentric or cam g. The cam g can be rotated by a hand lever. A tubular diaphragm m is mounted on the spindle 7c and enbloses the llatter fluid-tight the upper end'of the diaphragm being connected steam-tight at n to the casing 10.. i v' The apparatus works as follows. plate p be forced downwards by rotation of the cam it presses by means of the spring o on the disc 12 so that the spindle r: and the valve 'a are forced downwards and the valve is opened. According to the position of the cam g the valve lu is closed or opened to any desired extent. Otherwise the valve is under the pressure of the tubular system. On in- 'creasig pressure in thecasing 10 the tubular diaphragm m is more or less collapsed and moves the spindle 7c upwards against the actionpf the spring 0 so that the valve v is whollyor partly closed untilthe pressure decreases. The play of the spring o is such that the automatic action can take place independently of any manual adjustment.

The controlling valve as illustrated in Fig. 2 may be made without the spring 0 and the plate p, as shown at 23 in Fig. 4. The object of these parts is to maintain the pressure within certain limits. When the partsv o, p are dispensed With, the quantity of liquid in the system`is vcalculated to such extent that the pressure will not exceedv a given limit even if the liquidhis completely evaporated.

The volume 'of liquid must consequently be at -a certain ratio with respect to the capacity of.

the system including thecasing 10 of the control valve. f\ n s Referring nw to Fig. 4, this shows a fuelyfired central heating system. The storage -[f the i sorbed by the evaporator coils 16, 17 and 18. From these the rising steam pipe 19 leads to the several heating stations to which branch steam pipes 20 are led by siphons 21. From the heating station 22 the condensate flows out through the regulating valve 23 to the branch condensate pipe 24 through a siphon 25 to the rising condensate pipe 26 in which is disposed a collector 27. From the latter a pipe 28 leads to a collecting valve 29 hereinafter described from which the condensate is led through the pipe 30 to headers Z of the evaporator coils 16, 17, 18. The valve 23 corresponds to the valve in Fig. 2 and each yof the several heating stations is provided with an escape valve 23. The valve 29 essentially corresponds in construction to the valve according to Fig. 2,- but in the constructional form of Figure 4 a diaphragm 31 is shown which carries a guiding member 32 in which is a weak spring 33 which acts against the head 34 of a conical valve 35, so that the latter which controls the flow to the tube 30 serves simultaneously as a check valve. d

The apparatus works as follows:

The heating medium evaporated in the coils 16, 17 and 18 is led in the described manner to the heating station or stations 22 whose adjustable valves 23 are opened, and then flows to the collector 27 and through the pipe 28 to the main valve 29 and back again through the tube 30 into the evaporator coils 16, 17 and 18. In this manner the steam-or vapour from the heating medium is led to the several heat consuming stations, for example kitchens, the storage block 14 being disposed for example in a cellar. The branch pipe 2,1 from the rising steam or vapour pipe 19 is disposed somewhat higher than the heating station 22, in order to avoid permanent loss,

otherwise the heating position and branch pipe during inoperative periods would fill' with condensate through radiation losses. Similarly, the condensate escape branch pipe 24, is so arranged that it lies-somewhat below the lowest heating station and that the condensate branch pipe 24 may always be full of condensate for which purpose the said pipe is connected to the rising bend 25.

If now a longer working pause takes place' during which all the valves 23 are closed the pressure in the condensate pipe is reduced because thepipel has a lower Itempera-ture thanthe steam or vapour pipe. In consequence of this the check valve 29 is closed and in spite of the reduced pressure no new liquid is introduced into the system. By

' cooling at the heating stations 22 and the branch steam pipes 20 the existing steam or vapour in the branch pipes is condensed `until no more uid is in the evaporator, so that the pressure of the system falfs further.

The losses during long non-working pauses are thus greatly reduced. The redced pressure in the condensate pipe 26 as against that in the steam pipe 19 ceases only when the valve 23 of'a heating station is again opened, so that liquid again flows to the evaporator. In order to prevent a higher pressure than is permissible a safety valve not shown can be provided and the escaping steam can be discharged and led to any desired place of'use, say for heating water.

In order to produce large quantities of steam such as are required in central heating installa-tions several evaporator coils 16, 17 and 18 are required which as shown are arranged below one another. In order that these coils may be charged as uniformly as possible but not quite full, overflow pipes u are arranged in both the upper inlet headers 2, whichpipes project downwardly approximately vertically from the headers and lead to the evaporator header below. The overflow pipes are so arranged that the liquid arriving by the pipe 30 must first flow past the overflow pipes in order to reach the evaporator-coil. By reason of such `an arrangement a quicker delivery of part of the iuid to the second coil takes place through the overflow pipe without the first coil being completely filled. This arrangement of the overflow' pipes ensures that the liquid in the evaporator does not fill the pipes to their complete height so that knocking is avoided and the heating medium is heated and/or super-heated more quickly and uniformly.

If the pressure due to an increased steam production increases, the valve 35 closes by the action of the diaphragm 31 upwardly against the action ofthe spring 0 so that on reaching the predetermined pressure the valve is closed. By the use of the Weak spring 33 for the check valve the hereinbefore` described actions can follow one another undisturbed.

The .arrangement can also be so constructed that at any heating station, for example in a kitchen, a complete storage hearth is installed whose storage block is chargedonce or twice daily by the highly heated heating medium from .a central source of heat.

This arrangement has the advantage that the losses prevailing under the existing condition at any time in the rising and branch lfpipes are limited to the short storage time `clays and holidays with excess current in' order to avoid attending the furnaces at the Acentral installations on these days.

I claim:

1. `A heating installation comprising a storage block, means for heating said block, a liquid evaporator in said block, a heating station, a pipe line comprising an outflow and a return branch connecting said block with said heating station, a valve in'said return branch adapted to control the flow a liquid evaporator in saidblock, a heating station, a ipe line comprising an outiow and a return ranch connecting said block with said heating station, a valve in said return 7branch adap ed to control the flow of condensate ther `n, and a diaphragm controlled by the pressure in said pipe line for operating said valve in conformity with the pressure. f

3. A heating installation comprising a storage block, means for heating Jsaid block, a liquid evaporator in said block, a heating station, apipe line comprising an outiiow and a return branch connecting said block with said heating station, a valve in said return branch adapted to control the ilow'of condensate therein, manual meansfor regulating said valve, and resilient means interposed between said regulating means and the body of said valveior transmitting power Afrom said regulating means to \said valve.

4. A heating vinstallation comprising a storage block, means for heating said block,

a liquid evaporator in said block, a heatin statlon, a'pipe line connecting said bloc with said heating station, a frame, and tension members by which said block is suspended from said frame.

5. A heating installation comprising a closed system including a storage block, an evaporator in said storage block, a heat abstracting device at a higher level than saidevaporator, a pipe line connectingsaid evaporator andpsaid heat abstracting device, and

. means intermediate said evaporator and said heat abstracting device for regulating the How of liquid in said pipe line.

6. A heating installation comprising a storage block, means 4for heating said block, a liquid evaporator in said block, a heating station, a4 closed system including an outowrand areturn branch connecting said` )block with said heating station, a valve in said return branch adapted to control the iiow of condensate therein, manual means for regulating said valve, and a tubular spring of corrugated axial section interposed between said'regulating means and the ody of said valvefor transmitting power from said regulating means to said valve.

7. A heating installation comprising a closedsystem including a storage block, an

evaporator in said storage block, a heat abstracting device comprismg a grid and ar'- ranged at a. higher level thansaid evaporator, a pipe line comprising an outflow and a return branch connecting said block with said device, an upward bend in said outiiow branch extending to above saidgrid, and an -automatic regulating valve in said return tem extending from said block to said device.

and including an evaporator in said block, an outiow and a return pipe intermediate said evaporator and said device, and an automatic regulating valve in said return pipe. In testimony whereof I have signedl my name to this specification.

- WILHELM PFEIFFER.

CERTIFICATE oF CORRECTION.

Patent No. 1,815,115. Granted my 21, 1931, 10

WILHELM PFEIEEER.

Itis hereby certified that error appears in the above nur'nbered patent requirf ing correction as follows: In the grant, and in the. heading to theprinted specilication, title ofinvention, for-"Heating Insulations"'read Heating Installation;

and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office. Signed and sealed this 3rd day of. November, A. D. 1931.

M. J. Moore,

. (Seal) Acting Commissioner .of Patents. 

